1. Field of the Invention
The present invention relates to containment systems for hypodermic needles and other sharp medical instruments, and more particularly to containment systems permanently encapsulating and containing hypodermic needles to prevent reuse and accidental needle sticks.
2. Background and Related Art
The handling and disposal of used medical instruments, particularly sharp medical instruments such as hypodermic needles, suture needles, lancets, trocars, scalpel blades and the like is a major problem facing healthcare professionals. Blood-born pathogens can be easily transmitted by inadvertent contact with the used medical instrument such as by accidental needle sticks.
In order to avoid such accidental needle sticks, especially immediately after using the needle, the healthcare professional will attempt to cover the needle with a protective cap or sheath so that the instrument can be safely transported for disposal. The provision for caps and sheaths affords some degree of protection, however many accidental needle sticks occur while trying to place the cap or sheath back on the needle in preparation for transport for disposal.
In the absence of re-capping or re-sheathing, quite often the used medical instrument is transported uncovered to a sharps container which ideally is located proximate to the site. The sharps container holds several used medical instruments in a hard puncture-resistant package which is subsequently collected for final disposal. However, this still requires the healthcare professional to handle and transport the unprotected needle after use. Also, the collected used instruments remain on site in the sharps container until collected for final disposal.
The art has seen many devices for capping, closing and sheathing used sharp medical instruments for disposal. Many of these devices simply enclose the entire medical instrument, or at least the sharp portion thereof in a protective enclosure. Other of these devices attempt to encapsulate or surround the used medical instrument with a composition which hardens around the sharp portion of the instrument, providing permanent containment and protection.
One such encapsulation system uses a two-part hardenable compound provided in a container (e.g. a needle cover) which accepts a sharp medical instrument such as a hypodermic needle. The container supports a hardenable resin such as a cyanoacrylate ester and a filler of particulate matter in spaced separation. The filler includes an accelerator which is used to speed up the hardening of the resin. The resin and the filler accelerator are separated by a rupturable partition such as thin glass. The used medical instrument, such as a needle, is inserted into the container, rupturing the glass membrane between the two components, thereby causing the components to come together and harden around the needle.
Such encapsulation systems have several disadvantages. First, it can be difficult and hence expensive to properly manufacture such systems, as the small scale of such systems necessitates care and precision in manufacturing. If any manufacturing deficiencies allow the two-part hardenable compound to mix before the intended time, the attempt to insert the needle into the encapsulation system may fail, and an additional system will be needed. Additionally, such systems of necessity require two separate devices for protecting the hypodermic needle before and after use: a standard cap or cover for protecting the needle before use, and an encapsulation cap or cover for after use of the needle. The use of multiple caps or covers results in extra waste, extra costs, extra time spent seeking to ensure that the correct cap or cover is used, etc. Finally, such systems may be prone to inadequate mixing of the two-part hardenable compound, such that permanent encapsulation of the needle is not achieved.